In conventional practice, supermarkets and convenience stores are equipped with refrigerated merchandisers, which may be open or provided with doors, for presenting fresh food or beverages to customers while maintaining the fresh food and beverages in a refrigerated environment. Typically, cold, moisture-bearing air is provided to a product display area of the merchandiser by passing an airflow over the heat exchange surface of an evaporator coil, or evaporator. A suitable refrigerant is passed through the evaporator, and as the refrigerant evaporates while passing through the evaporator, heat is absorbed from the air passing through the evaporator. As a result, the temperature of the air passing through the evaporator is lowered for introduction into the product display area of the merchandiser.
Such a prior-art refrigerated merchandiser 10 is shown in FIG. 1. The merchandiser 10 includes a case 14 generally defining an interior bottom wall 18, an interior rear wall 22, and an interior top wall 26. The area bounded by the interior bottom wall 18, interior rear wall 22, and the interior top wall 26 defines a product display area 30, in which the fresh food and/or beverages are stored on one or more shelves 32. The case 14 includes an open front face to allow customers access to the fresh food and/or beverages stored in the case 14.
The case 14 also generally defines an exterior bottom wall 34 adjacent the interior bottom wall 18, an exterior rear wall 38 adjacent the interior rear wall 22, and an exterior top wall 42 adjacent the interior top wall 26. A lower flue 46 is defined between the interior and exterior bottom walls 18, 34 to allow for substantially horizontal airflow throughout the lower flue 46. The interior bottom wall 18 includes an opening 50 to allow communication between the product display area 30 and the lower flue 46 allowing air from the product display area 30 to be drawn into the lower flue 46. A rear flue 54 is defined between the interior and exterior rear walls 22, 38 and is fluidly connected with and adjacent to the lower flue 46. The rear flue 54 allows for substantially vertical airflow throughout the rear flue 54. An upper flue 58 is defined between the interior and exterior top walls 26, 42 and is fluidly connected with and adjacent to the rear flue 54. The upper flue 58 allows for substantially horizontal airflow throughout the upper flue 58. The interior top wall 26 includes an opening 62 to allow communication between the product display area 30 and the upper flue 58 allowing airflow in the upper flue 58 to be discharged into the product display area 30. When combined, the lower flue 46, the rear flue 54, and the upper flue 58 comprise an air passage separate from the product display area 30.
The refrigerated merchandiser 10 also includes some components of a refrigeration system (not entirely shown) therein. One or more fans 66 are located within the lower flue 46 toward the back of the case 14 to generate an airflow through the lower, rear, and upper flues 46, 54, 58. An evaporator 70 is located within the rear flue 54 toward the bottom of the case 14. The evaporator 70 is positioned downstream of the fans 66 such that the airflow generated by the fans 66 is forced through the evaporator 70. The refrigeration system may also include other components (not shown), such as one or more compressors, one or more condensers, a receiver, and one or more expansion valves, all of which may be remotely located from the refrigerated merchandiser 10.
The evaporator 70 is configured to receive a liquid refrigerant from the receiver. As is known in the art, the liquid refrigerant is evaporated as it passes through the evaporator 70 as a result of absorbing heat from the airflow passing through the evaporator 70. Consequently, the temperature of the airflow passing through the evaporator 70 decreases as it passes through the evaporator 70. The heated, or gaseous refrigerant then exits the evaporator 70 and is pumped back to the compressor(s) for re-processing into the refrigeration system.
Downstream of the evaporator 70, the refrigerated airflow is routed vertically through the rear flue 54, and horizontally through the upper flue 58 before being discharged from the upper flue 58 via the opening 62 in the interior top wall 26. After being discharged from the opening 62 in the interior top wall 26, the refrigerated airflow moves downwardly along the open front face of the refrigerated merchandiser 10 before being drawn back into the opening 50 in the interior bottom wall 18 for re-use by the fans 66. This portion of the refrigerated airflow is known in the art as an air curtain 78.